The present invention relates to a design support apparatus for supporting work to design products and more particularly to method and apparatus for creating shape data.
In recent CAD/CAM/CAE systems, sharing of data has made cooperation among a CAD system, a CAE system and a CAM system extremely intimate. In other words, the flow of processing procedures has been realized substantially in which data for analysis is generated from three-dimensional data created by the CAD system and analyzed/evaluated by the CAE system and then the data is sent to the CAM system to create NC data for production working.
But in creation of the three-dimensional shape data giving a cardinal point of these processes, this type of data is restricted to figure data expressible on a computer and therefore only geometrical information in combination of lines and planes can be inputted. Accordingly, in a step of analytical calculation by the CAE system and in a step of production working by the CAM system, these steps are frequently accompanied by return work to confirm an intention of a design by a designer. Under the circumstances, methods for creating a shape in a unit of working operation of an NC machine in the phase of the three-dimensional CAD system have been proposed in, for example, JP-A-10-207523, JP-A-08-161378 and JP-A-09-245071.
Methods for supporting evaluation of working costs and assembling costs during product design have been disclosed in, for example, JP-A-2001-236373, JP-A-2001-222441 and JP-A-11-120249. In these methods, attributes such as cost and working method are inputted in respect of individual parts of three-dimensional CAD data and are used for calculation of a total cost. Disclosed in JP-A-08-161378, for instance, is a method according to which working costs are calculated in a three-dimensional CAD system by using a cost table corresponding to operations (bending, boring, cutting and the like) for working a plate structure. Also disclosed in, for example, JP-A-2001-142929 and JP-A-10-334127 are methods for calculating estimated costs by changing design parameters (size, quality of material and the like) of a three-dimensional CAD shape template prepared in advance.
For a product, a variety of working methods and assembling methods are available depending on demanded product specifications. There is a demand for a design environment that can take into account such factors as changes in production line, advance in working technology/assembling technology, design changes considering the influence of environment and variations in raw material costs. In order to reduce the return work for confirming a design intention by a designer in the CAE work and production working processes, shape data exhibiting the design intention in a design process must be taken over to the downstream CAE work and production process.
Contrarily, by studying the workability, assembling efficiency and production cost early in the design phase, the total term of product development can be shortened. To this end, a tool is needed which can permit a designer, who is being engaged in design by considering the production process under availability of variations of selectable working and assembling means, to design by studying a variety of working means on the screen and making himself or herself of conscious of working costs and assembling costs.
In the case of a conventional shape data creating method, in a specified working means, parameters such as, for example, the quality of a material to be worked, the tool diameter and the main spindle rotational speed are inputted in a unit of working operation of the NC machine and for example, working costs corresponding thereto are calculated on the basis of a parts table. But a production working method for detailing operation definitions of a cutter in individual phases of rough machining, semi-machining and finishing may preferably be determined in many cases on the CAM system side from the standpoint of high efficiency and work for setting detailed working operations in the phase of the CAD data creation is very laborious and time-consuming.